RE: [CAD_CAM_EDM_DRO] Re: Cutting the Hex surfaces.

Thanks Chris,

Makes sense. I sketched out the movement on the back of an envelope (only
thing nearby to write on) and to my surprise, the tip of the spinning tool
tip has to follow a sin curve to track a straight line on the other spinning
surface. Since the spinning tool tip is by default scribing a sin curve...
So simple. Makes sense too that if you want a hex nut then you need six
cutters.

John Dammeyer

>
> No tricks, no moving X axis, only the Z axis is moving to take
> succesive passes. There are machines that do have the X axis goin
> in and out during the rotation of the spindle, but that process is
> used for turning pistons (as they are not round, but oval). I
> forget what that is called - sorry, getting old.
>
> In polygon turning, the flycutter (the Orange tool in the video) is
> spinning just like a flycutter or even a face mill. The main
> spindle is spinning the workpiece in the opposite rotation. As the
> fly cutter passes by the spinning workpiece, it creates a very near
> flat surface on the workpiece. The ratio of speed and number of
> teeth control the number of flats. The ratio between the two
> diameters (part and cutter) determines, to a certain degree, how
> flat the surface will be.
>
> Programming is incredibly easy...
>
> M123 'M code to synchronize spindles
> G97 S2000 M03 'main spindle
> S1000 M04 'driven tool
> G00 X1.0
> G01 Z-.5
> G00 X2.0
>
> That's it, all the "Magic" is in the rotation of the two items (Part
> and cutter) and their synchronization. The M123 is not the actual M-
> Code nor is M04 for controlling the rotation of the live tooling,
> but hopefully you get the idea.
>
> Remember, this process goes back to screw machines and automatics -
> prior to CNC. So, it all had to be done with: gearing, ratios, and
> mechanics. As insane as it all seems, it is really very simple.
>
> Chris
>